Shirtless for a good cause: Photos from the 2013 Colorado Firefighter Calendar debut

Just look at this guy. If you noticed he's not wearing a shirt, your senses are still working. But there's a reason why he's only half-dressed: Every year, many of the state's male and female firefighters gather to donate their time and rock-solid bods to a photo calendar that raises both funds and awareness for the Children's Hospital Colorado Burn Center. Over the weekend, photographer Nathan Federico stopped by the debut of the 2013 edition to snap the following photos of the models and their fans at Mile High Station.